There is a corporate income tax for all entities organized as a corporation and that have sources of income in Maine. The corporate income tax rate is graduated, starting at 3.5% for up to $350,000 in income to 8.93% for income that surpasses $3.5 million. With 12 loan programs, 11 tax credits, 9 grants, 3 preferential rates, and 3 tax refunds available, Maine offers 38 incentive programs. The state also has four free trade zones: Bangor, Madawaska, Belfast and Portland.